In construction of modern buildings often there is a simplification of the structure of buildings to minimize the number of types of elements needed to create the building or to include fixtures and fittings within a building. This results in a need for repetitious drilling of holes throughout a ceiling whether that be a false ceiling of sound absorbent panels or a concrete ceiling that forms the floor of the story above. The resultant dust or expelled material can therefore be small fibrous material or concrete dust that is of such a size that it is harmful to the lungs and eyes of the person drilling and therefore is a health risk. In these more aware times of health and safety requirements for workers, it is important to minimize health risk factors and fulfill the legal requirements of providing a safe working environment.
In the use of electric drills it is known such as in DE 3140776 to limit the amount of airborne resultant dust or particulate material by providing an elongate longitudinally compressible elastic cylindrical body portion. This shroud is mounted around the drill body and extends coaxially along the drill bit to its end with the body portion able to engage the surface of the work piece being drilled. However this article has the disadvantage of requiring a mechanism that is able to attach to the drill body. Due to the many different types of drills and therefore drill bodies the attaching mechanism must either be a complex or cumbersome attachment piece or be made in a multitude of different sizes. Also, because the cylindrical body portion is not fixed in relative position around the drill bit, accidental drilling through the side of the cylindrical body portion can occur. Still further, since the apparatus encloses the entire drill bit, it is not possible to see how far the drill bit has extended into the work piece.
It is also known such as shown in U.S. Pat. No. 3,850,254 and DE 3129375 to make use of a vacuum system that also requires a mounting body fitting around the body of the drill and connecting to a shroud. The shroud extends around the drill bit. The mounting body includes not only a fitting for mounting around the drill body but a conduit that is in fluid communication with the shroud such that the conduit can connect to a vacuum system and thereby extract any dust collected in the shroud around the drill bit while the drill is in operation. This complex system requires the use of an external vacuum system, a large mounting body fitting around the drill body and a shroud covering the drill bit that makes it very difficult to estimate the depth that the drill bit has extended into the work piece.
Accordingly, there remains a need for an improved drill attachment which is more versatile and allows a user to estimate the depth of travel of a drill bit within the workpiece. There is a further need for a drill attachment which is relatively simple in construction while permitting efficient dust collection. The present invention is directed to meeting these needs.